Need plans for a Dobson

[Brendan1952 (Brendan)]

Hi All,

I have been looking at various plans on the web for a DIY Dobson and was wondering if anyone here can recommend a site or set of plans that they have used that would be suitable for a novice telescope builder?

I am happy to buy books and plans etc but would prefer to have a recommendation first - sometimes what you get over the net falls short on quality!

I am a reasonably competent DIY type with good woodworking and metalworking skills but new to Astronomy.

Also does anyone know if there is a Sydney group for telescope builders similar the to Victorian one?

Thanks

Brendan

[mental4astro (Alexander)]

Hey Brendan,

I too have being looking for plans, but, grasshoper, there is much to learn before we tackle the Dragon.

Mate, plans forget it. You should have an idea of what you want, how big is practical, and larger or largest aint necessarily the best.

I've built a 10" dob (comercial optics), following this book: "Making and enjoying telescopes" Robert Miller & Kenneth Wilson. It's ok for the smaller diy project. Hey, it served me well. You can get a 2nd hand copy through internet book stores very cheaply.

My next project is considerably larger. Really, there is no getting past the 'holy grail' of scope manuals: "The dobsonian telescope; a practical manual for building large aperture telescopes" David Kriege & Richard Berry.

I had tried to skirt around it, but in the end, those who know more than us won out, so I got a copy.

What it describes is indipencible for properly understanding why and how dobs work.

Once you work out what size would work for you, look up that range of aperture in your prefered search engine, and use what you find to hybridize the design a little further.

I'm hoping to get stuck into a 17.5" puppy soon, however, I'm carefully planing its DNA, to achieve a workable design for me.

Hope I've helped. Don't rush it. Don't be shy to ask. This mob knows no fear or shame, !

Here's another suggestion, I'll be at the Randwick Girls' High astro night next Friday, follow the 'International year of astronomy' forum thread 'Sydney Astronomers'. I'll be there with my 10" scope. There will also be another ripper scope achiveable with the 'holy grail' book, Coooool.

[Blue Skies (Jacquie)]

Oh boy, this is where I wish (once again!) that I had some webpages on the principles of building a dob up. I've got some notes and various pages written but they've never been completed as a package (I always get stuck with the secondary cell). I'll drop you a pm with them if you're interested - or pm me if you'd like them.

I don't think you'll find any plans because part of the beauty of telescope building is that you individualise your telescope as you build it - take an idea from there and another idea from the next. But the main thing is as long as you meet the prinicples, your scope will work, and there are multiple ways of solving and meeting each principle. You get to choose which way to go, you're only limited by your creativity!

[okiscopey (Mike)]

Brendan, give Bintel (Binocular and Telescope Shop) a ring to see if they have this in stock:

'Build Your Own Telescope' by Richard Berry.

It has step-by-step instructions and plans for building a 6-inch Dob as well as a 10-inch plus three other scope types.

You can see from the attached photo of the inside that Berry gives a plan to get most of your Dob construction bits from just one sheet of plywood.

Cheers!

Mike.

[rmcpb (Rob)]

Berry is a good reference book but quite dated. The Kriege & Berry book is also starting to show its age. That said, both are really worthwhile reads if you are planning to build a scope then start searching in this forum, CN and ther Stellafane website.

[gary]

Originally Posted by mental4astro

Really, there is no getting past the 'holy grail' of scope manuals: "The dobsonian telescope; a practical manual for building large aperture telescopes" David Kriege & Richard Berry.

I had tried to skirt around it, but in the end, those who know more than us won out, so I got a copy.

What it describes is indipencible for properly understanding why and how dobs work.

Couldn't agree more than with the recommendation to have a copy of Kriege
and Berry's "The Dobsonian Telescope" as a vital reference.

As part of what we do, I'm lucky to get to correspond with lots of ATM'ers
from around the world.

What becomes clear from reading Kriege and Berry is that a successful
Dob is also the result of good engineering principals rather than just pure guess
work.

An analogy is bridge building. It would be unwise to build a bridge without
some background in structural engineering and materials.

Reading Kriege and Berry doesn't mean you need to build a "Kriege-style"
Dob, but it will help equip you with a working knowledge of questions like
"how large should the altitude bearings be" and whether you should offset
a secondary mirror or not.

Many ATM'ers don't stop at one scope, so I am sure that sooner or later
you will want to have this excellent reference book at your fingertips.

Hopefully you will find a Sydney-based ATM'er who can also provide some
inspiration. There is a nice offer there by Alexander. Have you joined
the Astronomical Society of New South Wales yet? I recommend
you do and then make absolutely sure you get to this year's
South Pacific Star Party. Be sure to walk around the observing field
with the telescope making judges. It is a great opportunity to see the work
of other ATM'ers, shake their hands and ask questions. Someone is likely
to have a telescope on the field there you will like enough that you will
want to clone it or use as a starting point for your own design.

Good luck with your project!

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
wildcard@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au

[Blue Skies (Jacquie)]

Originally Posted by rmcpb

Berry is a good reference book but quite dated. The Kriege & Berry book is also starting to show its age. That said, both are really worthwhile reads if you are planning to build a scope then start searching in this forum, CN and ther Stellafane website.

Yes, both good books to read, Brendan. The Berry designs look really clunky and chunky now with the move towards ultralight designs but the Kriege & Berry book was my bible for a while(when I was rebuilding a 17.5" for the club) - but all time I had the mantra "read it then throw the book away" in mind. What that means is that the books are very good at telling you why you need to do something, but not so good at how. As I mentioned above, there are principles to be met and you can meet them in different ways, or as a friend of mine liked to say "there are many ways to skin a cat." Looking around at what others are doing and trying to copy the bits you like from them is usually the best way to go.

[GrahamL]

An analogy is bridge building. It would be unwise to build a bridge without
some background in structural engineering and materials.

True Gary I made my scope from google images and a fair bit of internet without every seeing the book .. but in hindsight it would of made a few concepts a little easier to understand .. but the trial an error thing is also a little fun "to a point ".

good luck brenden its a great experiance

[tnott]

Having built several ultralight dobs of differing design, I regularly get people emailing me for "plans", which I do actually have as CAD files.

Unfortunately, every telescope will be slightly different, mainly depending on the diameter, thickness and focal length of the primary mirror, (they need to balance) so you may as well go the whole way and build something that suits your particular needs. If I did it with almost zero woodwork or metalwork skills then anyone can do it!

Smaller scopes (8-10 inches) are easier to build in some ways than big ones (16+), not to mention cheaper, so you may want to do one of those first to get some experience (I didn't -just jumped straight in with a 16 incher, then built a little 10 inch later).

The "Dobsonian Telescope" book is indispensable for the principles behind engineering a good dob, even if you do not go with the classic design as described in the manual.

As well, looking at plans without the background principles or explanation can be a bit incomprehensible!

Kits are available from Astrosystems and Dobstuff too, but that would take the fun out of it.

[Zubenel (Wes)]

I also couldn't agree more. I must apologise Tnott for the email the other day about a copy of your 16" plans. It was going to help me make up my mind to build a 16" ultra light. With being time poor for the foreseeable future and remembering how much time it took to build my 10" I think I was a bit desperate in the decission making process.Reading Kriege and Berry are great and i got alot of ideas from the web and other ATMers. so don't let me put you off Brendan as making your own is one of the most rewarding things you can do.
Cheers Zubenel

[Brendan1952 (Brendan)]

Hi All,

Thanks for all the suggestions, I have ordered both the books mentioned from overseas and will digest them before making any firm decisions.

Where do you suggest is the best place to find mirror prices? - I would like to get an idea of costs so I can make up a tentative budget.

Also is there anyone here who would be able / prepared to answer specific questions by PM as I get further down the planning path?

Regards

Brendan

[tnott]

What size are you thinking? Andrews in Oz has reasonable quality Chinese optics in the 6-12" range (http://www.andrewscom.com.au/site-section-10.htm). They also have the cheaper focusers,finders eyepieces etc.

Astrosystems in the US sells heaps of ATM stuff.http://www.astrosystems.biz/

Protostar sells secondaries, spiders and holders.http://www.fpi-protostar.com/

You can also buy a secondhand dob and use the optics for your own project. They come up regularly here on the buy/sell section. Often sold by people who find moving the commercial solid tube or split tube designs a pain.



If you want larger or the very best optics then you need to talk to Mark Suching here in Oz (http://users.tpg.com.au/masuch/dso/) or order from the US.

PMing is OK but using the forum will give you a wider range of answers and allow others to learn from your project too!

[Brendan1952 (Brendan)]

Hi,

In addidtion to the two books also mentioned I found this one on the net, Amateur Telescope Making (Patrick Moore's Practical Astronomy Series) has anyone here read it?
Is it worth getting in addition to the other two, it was published about 2002.

Regards

Brendan

[mental4astro (Alexander)]

Hi,

I'll be the last to knock anyone from furthering their library, but I do think you have plenty food for thought for now. Digest what you've got, you're in good hands with that. Anything else may just confuse, .

[tnott]

Originally Posted by Zubenel

I also couldn't agree more. I must apologise Tnott for the email the other day about a copy of your 16" plans. It was going to help me make up my mind to build a 16" ultra light. With being time poor for the foreseeable future and remembering how much time it took to build my 10" I think I was a bit desperate in the decision making process.
Cheers Zubenel

No worries. I'm happy to send people plans, but - they just won't work if you have a scope of different specs, they have some mistakes to be corrected manually afterwards and they would take a lot of explanation to understand them.

They would be more of a starting point for your own design.

It is nice to have a project to work on. If you just do it a bit at a time it's not too much hassle. The 16 inch tridob took me 12 mths, the 10 inch 3-pole dob about 6 weeks and the 22 inch about 3 months.

It is also very satisfying when you get the bugs worked out and can have the thrill of viewing the universe though something you have built yourself.

[Zubenel (Wes)]

Thanks Tnott . That would be of GREAT encouragement. I am very keen to use the laser cutting process and to have your diagrams will be of great assistance and a good starting point. I won't be going into it cold.
I would hope everyone understands that there are many factors which will change the design such as the weight of the materials , the focal length of the primary , the percentage illumination of the secondary in relation to the degree of filed of view etc. ////